What was found
SUSPECT BATTERY PACK 4 FOR CABIN AND OVERWING PAX EMERGENCY LIGHTING CONTROLLING MECH DOES NOT ILLUMINATE LIGHTS OVER SEAT 8 & FWD OVERWING EGRESS LIGHT WITH ONLY EMERGENCY BATTERY PACK PROVIDING POWER TO LIGHTS. INSPECTED, PERFORMED OPS CK IAW MM 33-50-00 EMERGENCY BATTERY PACK T/S CONTINUATION GAINED ACCESS TO ALL 4 BATTERIES, PERFORMED RESET OF ALL G SWITCHES PROBLEM CONTINUED INSPECTED BATTERY FUSES FOUND GOOD, INSPECTED CONNECTORS, NO DEFECTS NOTED. SWAPPED BATTERIES POSITION 3 WITH 4 & PROBLEM FOLLOWS TO POSITION 4. SWAPPED BACK. R & R POWER SUPPLY 3 IAW AMM 33-50-10, PERFORMED TOP CHARGE FOR 1 HR, PERFORMED EMERGENCY LIGHT TEST IAW AMM 33-50-00, FOUND SYS OK.